Mordo tracks down Pangborn, beats him up, steals his powers like Amon in Legend of Korra making Pangborn a paraplegic again, says powers shouldn't be used for selfish reasons (so that's why he took them back), says he's figured out what's wrong with the world; there's too many sorcerers in it.
What I'm curious about is where the hell did they start getting the ability to permanently rip someone's magic from them, and why wasn't this used elsewhere? "Oh btw Strange, if you run into this guy and manage to subdue him, using this trick will make him powerless permanently." But of course that'd make the plot too simple.